Mattress



FIG. 1 is a right side and top perspective view of a mattress showing my new design;

FIG. 2 is a right side elevational view of the mattress of FIG. 1, wherein the left side elevational view is a mirror image thereof;

FIG. 3 is a left bottom perspective view of the mattress of FIG. 1; and,

FIG. 4 is a front elevational view of the mattress of FIG. 1, wherein the rear elevational view is identical thereto.

The broken lines shown in the drawings are included for the purpose of showing environmental structure that forms no part of the claimed design. 

The ornamental design for a mattress, as shown and described. 